Wireshark-users: [Wireshark-users] Missing packet padding bytes on Mac

From: "Tatakis, Thomas (Tom)" <TTatakis@xxxxxxxxxxx>
Date: Thu, 19 Nov 2009 09:22:50 -0500

Hello,

I was recently debugging a CDP protocol issue with version 1.2.3 on a Mac platform.  The device I was debugging was adding padding bytes to the packets to an 8 byte boundary.  These bytes did not show up in the trace on the Mac platform.  However, when I used version 1.0.3 on a PC platform, these bytes did show up as part of the trace.

The Mac trace told me that "108 bytes on wire, 108 bytes captured" when in reality there were 112 bytes sent by the device.  The length field in the CDP packet only indicates 108 bytes but there are 112 bytes actually sent by the device.   The PC trace did indeed indicate "112 bytes on wire, 112 bytes captured".  I've looked for some sort of setup/configuration property that might fix the problem but can't seem to find one.  Is there something I am missing or is this a known problem (or an unknown problem)?

Thanks in advance for any help.
Tom